Salim bin Abdullah (may Allah have mercy on him) narrates from his father (Sayyiduna Abdullah bin Umar, may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "Bilal (may Allah be pleased with him) gives the adhan while it is still night, so eat and drink until Ibn Umm Maktum (may Allah be pleased with him) gives the adhan." Ibn Shihab (may Allah have mercy on him) said: Ibn Umm Maktum (may Allah be pleased with him) was blind; he would not give the adhan until it was said to him: You have reached the morning, you have reached the morning.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 2003